This invention relates to hydrofoils and hydrofoil mounting means in general, and in particular, to hydrofoils which can be repositioned.
It is well known that hydrofoils, such as fins which are attached to surfboards and other hulled craft, can be used to provide a desired reaction force when in motion relative to the fluid through which the hydrofoil is passing. As used hereinafter, the term "surfboard" shall include surfboards, boogie boards, wind surfing boards, and other hulled craft, which are manuevered by shifting the weight borne by the craft relative to the craft's center of gravity.
Hydrofoils are commonly used for directional stability but they have also been used to enhance manueverability of surfboards. It has become common practice to put a plurality of fins on the underside of surfboards. A fin located along the center line of the board generally is used to provide directional stability, but a pair of fins, commonly called "thruster fins", are generally spaced apart equally from the center line and are used to enhance turning response, that is, to increase maneuverability.
When first put into use, the edges of the thruster fins were generally aligned with the center line of the board. Soon after the introduction of the thruster fins, it was found that if the fins were toed-in, that is, the lines of the fins were not parallel but rather intersected at some point forward of the center of gravity of the board, turning response was enhanced. The current state of the art is such that most surfboards with thruster fins have the fins toed-in, but there is great disagreement with respect to the angle which the lines of the fins should make with respect to the center line of the board. Heretofore, a purchaser of a surfboard would have to, more or less, guess at which toe-in angle was proper or else purchase multiple boards. This invention alleviates that problem. A surfboard utilizing the unique and novel features of this invention allows the purchaser of the board to adjust the angle of the thruster fins to suit his or her weight, level of skill, and other factors.
Another problem associated with fins on surfboards involves the breakage of the fins from the boards. Heretofore, if the board struck an object with enough force to separate the fins from the board, both the board and the fins were severely damaged, and quite often, the damage was irreparable. This invention presents a fin which is designed to break-away with little or no damage when struck by a force severe enough to cause damage to conventional surfboards.
Other advantages and attributes to this invention will be discussed hereinafter and will be obvious upon reading of this specification.